Jersey Evening Post, Feb 25, 2017 (emphasis added): Radioactive cloud could be heading our way — A CLOUD of mysterious radioactive particles floating across Europe… could enter Jersey airspace, Environmental Health have said… scientists have yet to work out where the radiation comes from… Caroline Maffia, assistant director of Environmental Health in Jersey, said the department was aware of the situation but 24-hour-a-day air monitors placed across the Island had not detected anything yet. CAPTION: ‘We are not picking up anything at this moment. We are slightly out of the way of where it seems to be going but depending on wind direction we could detect something here,’ said Ms Maffia.http://jerseyeveningpost.com/news/2017/02/25/radioactive-cloud-could-be-heading-our-way/

Euronews, Feb 23, 2017: Europe baffled by “recent release” of radioactive Iodine-131… France’s IRSN stresses the amounts of radiation detected pose no health threats, but says its “detection is proof of a rather recent release”… Iodine-131, as described by the IRSN, is of anthropogenic origins – meaning an environmental pollutant originating from human activity… The mysterious origin of the radioactive element has baffled authorities, some of whom claim its presence could indicate either a secret Russian nuclear missile test launch, or a leak from a nuclear power plant. Iodine-131 has historical links to United States and Soviet nuclear tests… It has also been found among the radioactive contamination following Japan’s Fukushima reactor meltdown… The element is also commonly used in medicine… leading to speculation of a yet unidentified, or reported, leak at a pharmaceutical plant.

See also: ‘Mystery’: Radiation spikes being detected in many countries — US military secretly deploys ‘nuclear sniffer’ aircraft — Radioactivity levels quadrupled — Officials: Iodine-131 is “proof of rather recent release… the origin of which is still unknown”